The sonic signature needs to keep the treble detail, but increase the frequencyspectrum and add a more full sound.
声音特色方面，要保持高音的细节，但增加频响宽度，增加更多的饱满的声音。
2
Doppler effect can be demonstrated by manufactured device when the sound source is in circular motion. The frequencyspectrum is gained with chart spectrum analysis software.
利用自制装置演示了声源作圆周运动的多普勒效应，并应用图谱分析软件得到频率分布图。
3
Experimentally the spectrum of the sound field radiated by the cracked plate on collision is measured and the fundamental frequency is determined.